xref: /qemu/hw/intc/ioapic.c (revision f99b86b94987561580a94838766458e1c7b8685d)
1 /*
2  *  ioapic.c IOAPIC emulation logic
3  *
4  *  Copyright (c) 2004-2005 Fabrice Bellard
5  *
6  *  Split the ioapic logic from apic.c
7  *  Xiantao Zhang <xiantao.zhang@intel.com>
8  *
9  * This library is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2 of the License, or (at your option) any later version.
13  *
14  * This library is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
21  */
22 
23 #include "qemu/osdep.h"
24 #include "monitor/monitor.h"
25 #include "hw/hw.h"
26 #include "hw/i386/pc.h"
27 #include "hw/i386/apic.h"
28 #include "hw/i386/ioapic.h"
29 #include "hw/i386/ioapic_internal.h"
30 #include "include/hw/pci/msi.h"
31 #include "sysemu/kvm.h"
32 #include "target-i386/cpu.h"
33 #include "hw/i386/apic-msidef.h"
34 #include "hw/i386/x86-iommu.h"
35 
36 //#define DEBUG_IOAPIC
37 
38 #ifdef DEBUG_IOAPIC
39 #define DPRINTF(fmt, ...)                                       \
40     do { printf("ioapic: " fmt , ## __VA_ARGS__); } while (0)
41 #else
42 #define DPRINTF(fmt, ...)
43 #endif
44 
45 #define APIC_DELIVERY_MODE_SHIFT 8
46 #define APIC_POLARITY_SHIFT 14
47 #define APIC_TRIG_MODE_SHIFT 15
48 
49 static IOAPICCommonState *ioapics[MAX_IOAPICS];
50 
51 /* global variable from ioapic_common.c */
52 extern int ioapic_no;
53 
54 struct ioapic_entry_info {
55     /* fields parsed from IOAPIC entries */
56     uint8_t masked;
57     uint8_t trig_mode;
58     uint16_t dest_idx;
59     uint8_t dest_mode;
60     uint8_t delivery_mode;
61     uint8_t vector;
62 
63     /* MSI message generated from above parsed fields */
64     uint32_t addr;
65     uint32_t data;
66 };
67 
68 static void ioapic_entry_parse(uint64_t entry, struct ioapic_entry_info *info)
69 {
70     memset(info, 0, sizeof(*info));
71     info->masked = (entry >> IOAPIC_LVT_MASKED_SHIFT) & 1;
72     info->trig_mode = (entry >> IOAPIC_LVT_TRIGGER_MODE_SHIFT) & 1;
73     /*
74      * By default, this would be dest_id[8] + reserved[8]. When IR
75      * is enabled, this would be interrupt_index[15] +
76      * interrupt_format[1]. This field never means anything, but
77      * only used to generate corresponding MSI.
78      */
79     info->dest_idx = (entry >> IOAPIC_LVT_DEST_IDX_SHIFT) & 0xffff;
80     info->dest_mode = (entry >> IOAPIC_LVT_DEST_MODE_SHIFT) & 1;
81     info->delivery_mode = (entry >> IOAPIC_LVT_DELIV_MODE_SHIFT) \
82         & IOAPIC_DM_MASK;
83     if (info->delivery_mode == IOAPIC_DM_EXTINT) {
84         info->vector = pic_read_irq(isa_pic);
85     } else {
86         info->vector = entry & IOAPIC_VECTOR_MASK;
87     }
88 
89     info->addr = APIC_DEFAULT_ADDRESS | \
90         (info->dest_idx << MSI_ADDR_DEST_IDX_SHIFT) | \
91         (info->dest_mode << MSI_ADDR_DEST_MODE_SHIFT);
92     info->data = (info->vector << MSI_DATA_VECTOR_SHIFT) | \
93         (info->trig_mode << MSI_DATA_TRIGGER_SHIFT) | \
94         (info->delivery_mode << MSI_DATA_DELIVERY_MODE_SHIFT);
95 }
96 
97 static void ioapic_service(IOAPICCommonState *s)
98 {
99     AddressSpace *ioapic_as = PC_MACHINE(qdev_get_machine())->ioapic_as;
100     struct ioapic_entry_info info;
101     uint8_t i;
102     uint32_t mask;
103     uint64_t entry;
104 
105     for (i = 0; i < IOAPIC_NUM_PINS; i++) {
106         mask = 1 << i;
107         if (s->irr & mask) {
108             int coalesce = 0;
109 
110             entry = s->ioredtbl[i];
111             ioapic_entry_parse(entry, &info);
112             if (!info.masked) {
113                 if (info.trig_mode == IOAPIC_TRIGGER_EDGE) {
114                     s->irr &= ~mask;
115                 } else {
116                     coalesce = s->ioredtbl[i] & IOAPIC_LVT_REMOTE_IRR;
117                     s->ioredtbl[i] |= IOAPIC_LVT_REMOTE_IRR;
118                 }
119 
120                 if (coalesce) {
121                     /* We are level triggered interrupts, and the
122                      * guest should be still working on previous one,
123                      * so skip it. */
124                     continue;
125                 }
126 
127 #ifdef CONFIG_KVM
128                 if (kvm_irqchip_is_split()) {
129                     if (info.trig_mode == IOAPIC_TRIGGER_EDGE) {
130                         kvm_set_irq(kvm_state, i, 1);
131                         kvm_set_irq(kvm_state, i, 0);
132                     } else {
133                         kvm_set_irq(kvm_state, i, 1);
134                     }
135                     continue;
136                 }
137 #endif
138 
139                 /* No matter whether IR is enabled, we translate
140                  * the IOAPIC message into a MSI one, and its
141                  * address space will decide whether we need a
142                  * translation. */
143                 stl_le_phys(ioapic_as, info.addr, info.data);
144             }
145         }
146     }
147 }
148 
149 static void ioapic_set_irq(void *opaque, int vector, int level)
150 {
151     IOAPICCommonState *s = opaque;
152 
153     /* ISA IRQs map to GSI 1-1 except for IRQ0 which maps
154      * to GSI 2.  GSI maps to ioapic 1-1.  This is not
155      * the cleanest way of doing it but it should work. */
156 
157     DPRINTF("%s: %s vec %x\n", __func__, level ? "raise" : "lower", vector);
158     if (vector == 0) {
159         vector = 2;
160     }
161     if (vector >= 0 && vector < IOAPIC_NUM_PINS) {
162         uint32_t mask = 1 << vector;
163         uint64_t entry = s->ioredtbl[vector];
164 
165         if (((entry >> IOAPIC_LVT_TRIGGER_MODE_SHIFT) & 1) ==
166             IOAPIC_TRIGGER_LEVEL) {
167             /* level triggered */
168             if (level) {
169                 s->irr |= mask;
170                 if (!(entry & IOAPIC_LVT_REMOTE_IRR)) {
171                     ioapic_service(s);
172                 }
173             } else {
174                 s->irr &= ~mask;
175             }
176         } else {
177             /* According to the 82093AA manual, we must ignore edge requests
178              * if the input pin is masked. */
179             if (level && !(entry & IOAPIC_LVT_MASKED)) {
180                 s->irr |= mask;
181                 ioapic_service(s);
182             }
183         }
184     }
185 }
186 
187 static void ioapic_update_kvm_routes(IOAPICCommonState *s)
188 {
189 #ifdef CONFIG_KVM
190     int i;
191 
192     if (kvm_irqchip_is_split()) {
193         for (i = 0; i < IOAPIC_NUM_PINS; i++) {
194             MSIMessage msg;
195             struct ioapic_entry_info info;
196             ioapic_entry_parse(s->ioredtbl[i], &info);
197             msg.address = info.addr;
198             msg.data = info.data;
199             kvm_irqchip_update_msi_route(kvm_state, i, msg, NULL);
200         }
201         kvm_irqchip_commit_routes(kvm_state);
202     }
203 #endif
204 }
205 
206 #ifdef CONFIG_KVM
207 static void ioapic_iec_notifier(void *private, bool global,
208                                 uint32_t index, uint32_t mask)
209 {
210     IOAPICCommonState *s = (IOAPICCommonState *)private;
211     /* For simplicity, we just update all the routes */
212     ioapic_update_kvm_routes(s);
213 }
214 #endif
215 
216 void ioapic_eoi_broadcast(int vector)
217 {
218     IOAPICCommonState *s;
219     uint64_t entry;
220     int i, n;
221 
222     for (i = 0; i < MAX_IOAPICS; i++) {
223         s = ioapics[i];
224         if (!s) {
225             continue;
226         }
227         for (n = 0; n < IOAPIC_NUM_PINS; n++) {
228             entry = s->ioredtbl[n];
229             if ((entry & IOAPIC_LVT_REMOTE_IRR)
230                 && (entry & IOAPIC_VECTOR_MASK) == vector) {
231                 s->ioredtbl[n] = entry & ~IOAPIC_LVT_REMOTE_IRR;
232                 if (!(entry & IOAPIC_LVT_MASKED) && (s->irr & (1 << n))) {
233                     ioapic_service(s);
234                 }
235             }
236         }
237     }
238 }
239 
240 void ioapic_dump_state(Monitor *mon, const QDict *qdict)
241 {
242     int i;
243 
244     for (i = 0; i < MAX_IOAPICS; i++) {
245         if (ioapics[i] != 0) {
246             ioapic_print_redtbl(mon, ioapics[i]);
247         }
248     }
249 }
250 
251 static uint64_t
252 ioapic_mem_read(void *opaque, hwaddr addr, unsigned int size)
253 {
254     IOAPICCommonState *s = opaque;
255     int index;
256     uint32_t val = 0;
257 
258     switch (addr & 0xff) {
259     case IOAPIC_IOREGSEL:
260         val = s->ioregsel;
261         break;
262     case IOAPIC_IOWIN:
263         if (size != 4) {
264             break;
265         }
266         switch (s->ioregsel) {
267         case IOAPIC_REG_ID:
268         case IOAPIC_REG_ARB:
269             val = s->id << IOAPIC_ID_SHIFT;
270             break;
271         case IOAPIC_REG_VER:
272             val = IOAPIC_VERSION |
273                 ((IOAPIC_NUM_PINS - 1) << IOAPIC_VER_ENTRIES_SHIFT);
274             break;
275         default:
276             index = (s->ioregsel - IOAPIC_REG_REDTBL_BASE) >> 1;
277             if (index >= 0 && index < IOAPIC_NUM_PINS) {
278                 if (s->ioregsel & 1) {
279                     val = s->ioredtbl[index] >> 32;
280                 } else {
281                     val = s->ioredtbl[index] & 0xffffffff;
282                 }
283             }
284         }
285         DPRINTF("read: %08x = %08x\n", s->ioregsel, val);
286         break;
287     }
288     return val;
289 }
290 
291 /*
292  * This is to satisfy the hack in Linux kernel. One hack of it is to
293  * simulate clearing the Remote IRR bit of IOAPIC entry using the
294  * following:
295  *
296  * "For IO-APIC's with EOI register, we use that to do an explicit EOI.
297  * Otherwise, we simulate the EOI message manually by changing the trigger
298  * mode to edge and then back to level, with RTE being masked during
299  * this."
300  *
301  * (See linux kernel __eoi_ioapic_pin() comment in commit c0205701)
302  *
303  * This is based on the assumption that, Remote IRR bit will be
304  * cleared by IOAPIC hardware when configured as edge-triggered
305  * interrupts.
306  *
307  * Without this, level-triggered interrupts in IR mode might fail to
308  * work correctly.
309  */
310 static inline void
311 ioapic_fix_edge_remote_irr(uint64_t *entry)
312 {
313     if (!(*entry & IOAPIC_LVT_TRIGGER_MODE)) {
314         /* Edge-triggered interrupts, make sure remote IRR is zero */
315         *entry &= ~((uint64_t)IOAPIC_LVT_REMOTE_IRR);
316     }
317 }
318 
319 static void
320 ioapic_mem_write(void *opaque, hwaddr addr, uint64_t val,
321                  unsigned int size)
322 {
323     IOAPICCommonState *s = opaque;
324     int index;
325 
326     switch (addr & 0xff) {
327     case IOAPIC_IOREGSEL:
328         s->ioregsel = val;
329         break;
330     case IOAPIC_IOWIN:
331         if (size != 4) {
332             break;
333         }
334         DPRINTF("write: %08x = %08" PRIx64 "\n", s->ioregsel, val);
335         switch (s->ioregsel) {
336         case IOAPIC_REG_ID:
337             s->id = (val >> IOAPIC_ID_SHIFT) & IOAPIC_ID_MASK;
338             break;
339         case IOAPIC_REG_VER:
340         case IOAPIC_REG_ARB:
341             break;
342         default:
343             index = (s->ioregsel - IOAPIC_REG_REDTBL_BASE) >> 1;
344             if (index >= 0 && index < IOAPIC_NUM_PINS) {
345                 uint64_t ro_bits = s->ioredtbl[index] & IOAPIC_RO_BITS;
346                 if (s->ioregsel & 1) {
347                     s->ioredtbl[index] &= 0xffffffff;
348                     s->ioredtbl[index] |= (uint64_t)val << 32;
349                 } else {
350                     s->ioredtbl[index] &= ~0xffffffffULL;
351                     s->ioredtbl[index] |= val;
352                 }
353                 /* restore RO bits */
354                 s->ioredtbl[index] &= IOAPIC_RW_BITS;
355                 s->ioredtbl[index] |= ro_bits;
356                 ioapic_fix_edge_remote_irr(&s->ioredtbl[index]);
357                 ioapic_service(s);
358             }
359         }
360         break;
361     }
362 
363     ioapic_update_kvm_routes(s);
364 }
365 
366 static const MemoryRegionOps ioapic_io_ops = {
367     .read = ioapic_mem_read,
368     .write = ioapic_mem_write,
369     .endianness = DEVICE_NATIVE_ENDIAN,
370 };
371 
372 static void ioapic_machine_done_notify(Notifier *notifier, void *data)
373 {
374 #ifdef CONFIG_KVM
375     IOAPICCommonState *s = container_of(notifier, IOAPICCommonState,
376                                         machine_done);
377 
378     if (kvm_irqchip_is_split()) {
379         X86IOMMUState *iommu = x86_iommu_get_default();
380         if (iommu) {
381             /* Register this IOAPIC with IOMMU IEC notifier, so that
382              * when there are IR invalidates, we can be notified to
383              * update kernel IR cache. */
384             x86_iommu_iec_register_notifier(iommu, ioapic_iec_notifier, s);
385         }
386     }
387 #endif
388 }
389 
390 static void ioapic_realize(DeviceState *dev, Error **errp)
391 {
392     IOAPICCommonState *s = IOAPIC_COMMON(dev);
393 
394     memory_region_init_io(&s->io_memory, OBJECT(s), &ioapic_io_ops, s,
395                           "ioapic", 0x1000);
396 
397     qdev_init_gpio_in(dev, ioapic_set_irq, IOAPIC_NUM_PINS);
398 
399     ioapics[ioapic_no] = s;
400     s->machine_done.notify = ioapic_machine_done_notify;
401     qemu_add_machine_init_done_notifier(&s->machine_done);
402 }
403 
404 static void ioapic_class_init(ObjectClass *klass, void *data)
405 {
406     IOAPICCommonClass *k = IOAPIC_COMMON_CLASS(klass);
407     DeviceClass *dc = DEVICE_CLASS(klass);
408 
409     k->realize = ioapic_realize;
410     dc->reset = ioapic_reset_common;
411 }
412 
413 static const TypeInfo ioapic_info = {
414     .name          = "ioapic",
415     .parent        = TYPE_IOAPIC_COMMON,
416     .instance_size = sizeof(IOAPICCommonState),
417     .class_init    = ioapic_class_init,
418 };
419 
420 static void ioapic_register_types(void)
421 {
422     type_register_static(&ioapic_info);
423 }
424 
425 type_init(ioapic_register_types)
426